Everted filter device

ABSTRACT

Everting filter devices and methods for using the devices, including using the devices as intra-vascular filters to filter thrombus, emboli, and plaque fragments from blood vessels. The filter devices include a filter body nominally tubular in shape and having a large proximal opening. The filter body can extend from a proximal first end region distally over the non-everted exterior surface of the filter, further extending distally to a distal-most region, then converging inwardly and extending proximally toward the filter second end region, forming a distal everted cavity. The degree of eversion of the filter can be controlled by varying the distance between the filter first end region near the proximal opening and the closed second end region. Bringing the filter first and second end regions closer together can bring filter material previously on the non-everted filter exterior to occupy the distal-most region.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.13/325,733, filed Dec. 14, 2011, which is a continuation of U.S.application Ser. No. 12/581,960, filed Oct. 20, 2009, now U.S. Pat. No.8,092,486, issued on Jan. 10, 2012, which is a continuation of U.S.application Ser. No. 11/208,497, filed Aug. 22, 2005, now U.S. Pat. No.7,621,870 B2, issued Nov. 24, 2009, which is a continuation of U.S.application Ser. No. 10/096,624, filed Mar. 12, 2002, now abandoned, thecontents of each of which are hereby incorporated herein by reference.

FIELD OF THE INVENTION

The present invention is related generally to medical devices. Thepresent invention includes intravascular filter devices.

BACKGROUND OF THE INVENTION

Coronary vessels, partially occluded by plaque, may become totallyoccluded by a thrombus or blood clot causing myocardial infarction,angina and other conditions. A number of medical procedures have beendeveloped to allow for the removal of plaque from vessel walls or toclear a channel through the thrombus or clot to restore blood flow andminimize the risk of myocardial infarction. Carotid, renal, peripheral,and other blood vessels can also be blocked and require treatment. Forexample, atherectomy or thrombectomy devices can be used to removeatheroma or thrombus. Alternatively, in percutaneous transluminalcoronary angioplasty (PTCA), a guide wire or guide catheter is insertedinto the femoral artery of a patient near the groin, advanced throughthe artery, over the aorta, and into a coronary artery. An inflatableballoon is then advanced into the coronary artery, across a stenosis orblockage, and the balloon inflated to dilate the blockage and open aflow channel through the partially blocked vessel region. While somestenoses remain in place once dilated, others are more brittle, and maypartially crack and fragment, allowing the fragments to flow downstreamwhere they may block more distal and smaller coronary vessels, possiblycausing myocardial infarction, from that site. Consequences ofembolization include stroke, diminished renal function, and impairmentof peripheral circulation possibly leading to pain and amputation.

Saphenous vein grafts are often used to bypass occluded coronary vesselsin coronary artery bypass surgery. With time, the grafts can becomeoccluded with grumous. The grumous can also be dilated with balloons orremoved in other ways. The grumous can present an even more difficultmaterial to remove than thrombus, as the material is very friable, andlikely to break into smaller fragments during the removal procedure.

Distal embolic protection devices have been developed to prevent thedownstream travel of materials such as thrombi, grumous, emboli, andplaque fragments. Devices include occlusive devices and filters.Occlusive devices, for example distal inflatable balloon devices, cantotally block fluid flow through the vessel. The material trapped by theinflatable devices can remain in place until removed using a method suchas aspiration. However, aspiration cannot remove large particles becausethey won't fit through the aspiration lumen. Also, aspiration is a weakacting force and won't remove a particle unless the tip of theaspirating catheter is very close to the particle to be removed. Duringthe occlusion, the lack of fluid flow can be deleterious. In coronaryapplications, the lack of perfusing blood flow can cause angina. Incarotids, seizure can result from transient blockage of blood flow. Inboth coronaries and carotids it is not possible to predict who willsuffer from angina or seizure due to vessel occlusion. If a procedure isstarted with an occlusive device, it may be necessary to remove it andstart over with a filter device.

Some distal embolic protection devices include filters. The filters canbe advanced downstream of a site to be treated and expanded to increasethe filter area. Filtrate, such as emboli, can be captured in the filteruntil the procedure is complete or the filter is occluded. When thecapacity of the filter is reached, the filter becomes occluded, blockingfluid flow past the filter device. The filter may then be retracted andreplaced or left as is. If the filter is replaced with a freshunoccluded filter, extra wire motions are required along with extratime. While the replacement is occurring, there is a period of noembolic protection for the patient and a risk of dislodging emboliduring filter manipulation. If the filter is left in place, the vesselwill be occluded during the remainder of the procedure and the patientcan suffer the consequences of occlusion described earlier. Both choicesare less than optimal.

Another shortcoming of current filters relates to their use distal ofemboli sources when the emboli sources are located immediately proximalof a vessel bifurcation or trifurcation. Multiple filters may berequired, one for each vessel branch, which is cumbersome and may not bedone well, if attempted at all. Further, the use of multiple filters maynot be compatible with other needed equipment such as angioplastyballoons and/or stents.

Some physicians prefer to use filters while others prefer to useocclusive devices. Whether a particular procedure may call for use of anocclusive device or a filter device may not be known until midwaythrough the procedure. Occlusive distal protection devices are generallypreferred for use in carotid vessels where even tiny particles can causebig problems if they happen to lodge in a very important but smallartery. However, occlusive devices compromise fluoroscopic imaging dueto the lack of flow during radiopaque dye injection.

What would be desirable are intravascular filters capable of additionalfiltering after being occluded with thrombi, without being removed fromthe body. What would be advantageous are intravascular filters which canbe manipulated between a filtering mode and an occluding mode. Filtersthat can be used in the vicinity of a bifurcation would be beneficial.

SUMMARY OF THE INVENTION

The present invention provides everted filter trap devices and methodsfor using the everted filters. The devices can be used in body vesselsincluding the coronary, carotid, renal, neurological and cerebral bloodvessels, as well as ureters, and the respiratory and biliary tracts. Theeverted filters can include a tubular filter body having a largeproximal opening and a closed distal end. The filter body can extenddistally from a first end region near the filter body proximal opening,further extending over an intermediate, non-everted region, continuingdistally and everting over a distal-most region. The everting causes thefilter body exterior to converge inwardly and proximally to a closed,filter body second end region. The proximally extending and inwardlyconverging exterior surface of the filter body defines a distal, evertedcavity bounded distally by the distal-most extent of the evertingfilter. The distal everted cavity has exterior cavity walls which extendproximally back towards the proximal opening. The degree of eversion ofthe filter body may be changed through controlling the relativepositions of the filter body first and second end regions. When thefilter body diameter is held constant, proximally withdrawing theeverted second end region toward the first end region increases thedegree of eversion, increasing the distal everted cavity volume andlength and increasing the length of filter body exterior surface withinthe distal, everted cavity.

In use, an everting filter device can be advanced to a target regionwithin a body vessel region to be filtered. Some everting filter devicescan be advanced over a guide wire, while other devices can be advancedin a constrained state within a delivery sheath. The everting filterbody is preferably biased to expand radially outward to approach thetarget region vessel walls. The everting filter can be initiallydeployed in a minimally everted configuration, having a small distaleverted cavity volume and length. With time, the everting filterinterior surface near and around the filter distal-most region maybecome occluded with filtrate material. The everting filter may then befurther everted, by bringing the filter body first and second endregions closer together. This relative movement can bring the occludedbody material previously in the distal-most position to a positionwithin the distal everted cavity sidewalls. This relative movement alsobrings filter material previously on the outside, non-everted surfaceregion of the filter to the distal-most position, thereby providingfresh, non-occluded filter material.

The everting filter can provide fresh, porous, non-occluded filtermaterial while proximally relocating the occluded filter material sothat the perfusing vessel fluid flow is directed sideways over theoccluded material rather than directly into the material. When theeverting filter capacity is reached or the filtering is otherwisecomplete, the filter can be proximally retracted within a filter capturedevice, for example, a sheath. The captured, filtrate containing filtercan then be withdrawn from the patient's body.

Some everting filter devices have a first, proximal shaft coupled to thefilter body first end region and a second, distal shaft coupled to thefilter body second end region, allowing the relative and absolutemovements of the filter body end regions to be independently controlled.In some filter bodies, the distal shaft can be slidably disposed withinthe proximal shaft. In some embodiments, the distal shaft has a lumenfor passing a guide wire therethrough. Some everting filter devices haveonly a single shaft coupled to the filter body second end region in thedistal everted cavity. Such everting devices can rely on the radiallyoutward expansion of the filter body against the vessel walls to anchorthe filter body. The relative movement of the single shaft and coupledeverted distal end of the filter body can control the degree of eversionby moving the single shaft relative to the anchored filter body.

Some everting filter devices can operate as filtering/occluding devices.One group of such devices have a filter body which includes an occludingportion and a filtering portion. The device can be operated in filteringmode by bringing the filtering portion to the distal-most region of thefilter. The occluding mode can be attained by bringing the occludingportion of the filter body to the distal-most region. Some devices havea proximal filtering portion followed by a more distal occludingportion, while other devices have a proximal occluding portion followeddistally by a filtering portion. The degree of eversion can controlwhether the filtering portion is disposed about the outsidecircumference of the filter body, in the distal-most region, or withinthe everting distal cavity to form the side walls. Suchoccluding/filtering devices can allow postponing the decision to use afiltering device or an occluding device past the time of deploying thedevice within the patient's vessel.

Other everting filter devices can be used as thrombectomy devices. Thethrombectomy devices preferably have a large proximal opening and aproximal hoop or loop disposed near the proximal opening. The proximalloop can be stiff and attached to the filter body near the proximalopening. The thrombectomy device can be deployed distally of a thrombus,then retracted proximally through the thrombus, with the proximal loopdislodging the thrombus from the vessel wall. The thrombus can becaptured within the filter body interior, with the filter body elongatedduring the capture. One mode of elongation begins with a highly evertedfilter body and then decreases the degree of eversion by proximallyretracting a shaft coupled to the filter body proximal end region. Thethrombectomy device carrying the thrombus can later be retracted withina tubular capture device.

Filters according to the present invention can be used to filter vesselregions immediately proximally upstream of a vessel bifurcation ortrifurcation. In one method, the everted filter is advanced to theregion in an elongated, radially reduced state, then more fully everted,expanding the filter exterior non-everted walls against the vesselinterior walls. The filter can be both radially expanded andlongitudinally shortened to approach and benignly anchor the filter tothe vessel walls, providing coverage across the vessel proximal of thebifurcation. The filter effectively covers all the vessel branchesdistal of the branching, providing protection. The filter can be locatedin the region distal of the trunk but proximal of the branches.

Everted filters also have the advantage of rendering the filterrelatively independent of the guide wire to prevent unwanted movement ofthe filter during motion of the guide wire. In some methods, the evertedfilter devices are used primarily to provide distal embolic protectionand are advanced over a guide wire, where the guide wire can haveanother device advanced over the guide wire proximal of the filter. Inother methods, the additional proximal device is used to remove ordilate plaque or thrombus, where the device is advanced over the filtershaft or tube, which is advanced over the guide wire. As the proximaldevice is exchanged over the guide wire, force is brought to bear on theguide wire, which can dislodge the guide wire and the filter. Theeverted filter has the advantage of rendering the filter comparativelyinsensitive to guide wire motion, so that guide wire movements do not aseasily dislodge the filter. In particular, sliding, translationalmovements of the guide wire through an everted filter band of thepresent invention do not apply significant force on the filter. In onemethod, an everted filter is used as the distal end to a guide wire,where the filter is used primarily as a distal guide wire anchoringdevice. In another method, the filter has a tubular shaft, and the guidewire passes through the tube.

The everted filters also provide a filter device able to significantlyincrease the interior volume of the filter after positioning the filterin a vessel region. An everted filter can be advanced to a vessel sitein a compressed state, having a small volume, small profile, and a highstrand density due to a small inter-strand distance and pore size. Inplace, the filter can be both elongated and radially expanded todecrease the strand density and increase the pore size and filterinterior volume.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the distal portion of an everted filterdevice having a filter body, a shaft, an everted distal-most region, afixed distal band, and an axially slidable proximal band;

FIG. 2A is a side view of the everting trap of FIG. 1;

FIG. 2B is a side view of the everting trap of FIG. 1, shown in anelongated configuration having the proximal band slid proximally awayfrom the distal band of FIG. 2A;

FIG. 2C is a side view of the everted filter device of FIG. 2A, shown inaxially foreshortened configuration, having the proximal band sliddistally toward the distal band of FIG. 2A;

FIG. 3A is a fragmentary, longitudinal, cross-sectional view of aneverted filter device everted distal region, having the filter bodyinterior surface secured to the shaft distal region, with the filterbody biased to evert;

FIG. 3B is a fragmentary, longitudinal cross-sectional view of theeverted filter device of FIG. 3A, shown in a small profile, elongatedconfiguration;

FIG. 3C is a fragmentary, longitudinal, cross-sectional view of aneverted filter device distal region having the filter body exteriorsurface mated to the shaft and having a conical shape;

FIG. 3D is a fragmentary, longitudinal, cross-sectional view of aneverted filter device distal region having the filter body exteriorsurface mated to the shaft distal region and having a separated,diverging everted distal cavity;

FIG. 3E is a fragmentary, longitudinal, cross-sectional view of aneverted filter device distal region having the filter body exteriormated to the shaft external surface and having a less separated,converging everted distal cavity;

FIG. 3F is a fragmentary, longitudinal, cross-sectional view of theeverted filter device of FIG. 3D, having an atraumatic tip;

FIG. 4A is a fragmentary, perspective view of an everted filter devicehaving a proximal shaft secured to a filter body proximal region and adistal shaft secured to the filter body distal region;

FIG. 4B is a fragmentary, perspective view of an everted filter devicehaving a proximal shaft coupled to the filter body proximal region andthe distal shaft coupled to the filter body distal region, with thedistal shaft slidably coupled to the proximal shaft through a collar;

FIG. 4C is a fragmentary, perspective view of the distal portion of aneverted filter device having a proximal shaft secured to the filter bodyproximal region and the distal shaft secured to the filter body distalregion, with the distal shaft slidably received within a lumen in theproximal shaft;

FIG. 5A is a fragmentary, perspective view of a filter trap similar tothat of FIG. 4B, but having a curved distal shaft extending transverselyaway from the proximal shaft;

FIG. 5B is a fragmentary, perspective view of an everted filter devicesimilar to that of FIG. 4C, but having a curved distal shaft;

FIG. 5C is a fragmentary, perspective view of an everting filter similarto that of FIG. 5A, with a doubly curved distal shaft;

FIG. 6 is a fragmentary, side view of one frictional lock deviceincluded in some everted filter device devices;

FIG. 6A is a transverse, cross-sectional view taken through 6A of FIG.6;

FIG. 6B is a perspective view of the frictional lock of FIG. 6;

FIG. 7 is a fragmentary, perspective view of an everted filter devicehaving a slidable proximal ring and two proximal filter body openings;

FIG. 8A is a fragmentary, longitudinal, cross-sectional view of aneverting filter device similar to that of FIG. 4C shown disposed withina delivery tube prior to use;

FIG. 8B is a fragmentary, longitudinal, cross-sectional view of theeverting filter device of FIG. 8A, after the filter has been deployed ina vessel and at least partially occluded with filtrate material;

FIG. 8C is a fragmentary, longitudinal, cross-sectional view of theeverting filter device of FIG. 8B, after the filter has been furthereverted by proximally retracting the distal ring, thereby distallyadvancing unoccluded filter material to the distal-most region of thefilter device;

FIG. 9 is a fragmentary, perspective view of an everting filter devicehaving a proximal shaft secured to the filter body mouth region with afilament or string;

FIG. 10A is a fragmentary, perspective view of an everting filter devicehaving the filter body everted end coupled to the shaft and the filterbody proximal mouth region coupled to the shaft through fasteningmembers;

FIG. 10B is a fragmentary, perspective view of the everting filterdevice of FIG. 10A in the fully everted position, where the fasteningmembers are tethers;

FIG. 10C is a fragmentary, perspective view of the filter device of FIG.10B, shown in a less everted position;

FIG. 11 is a fragmentary, perspective view of an everting filter devicehaving a central tube, a proximal filter body mouth region, and pullstrings threaded through the proximal mouth region and central tube;

FIG. 12A is a fragmentary, perspective view of an occluding/filteringdevice having an occluding distal region, shown in the occludingposition;

FIG. 12B shows the occluding/filtering device of FIG. 12A in a moreeverted, filtering position;

FIG. 13A is a fragmentary, perspective view of an occluding/filteringdevice having a filtering distal region and an occluding proximalregion, shown in the filtering position;

FIG. 13B is a fragmentary, perspective view of the occluding/filteringdevice of FIG. 13A, shown in the more everted, occluding position;

FIG. 14 is a fragmentary, perspective view of a drug delivery cathetersharing some features with the device of FIG. 12A;

FIG. 15A is a fragmentary, perspective view of an occluding/filteringdevice having an inflatable balloon disposed within a mesh filter body,shown in the inflated, occluding configuration;

FIG. 15B is a fragmentary, perspective view of the occluding/filteringdevice of FIG. 15, shown in the uninflated, filtering configuration;

FIG. 16 is a fragmentary, longitudinal, cross-sectional view of athrombectomy device having a proximal tube, a distal shaft slidablydisposed within the proximal tube, a filter mesh filter body, and arigid proximal loop, shown disposed distally of a thrombus;

FIG. 17 is a fragmentary, longitudinal, cross-sectional view of thethrombectomy device of FIG. 16, shown after the proximal loop hasdislodged the thrombus and the filter body has captured the thrombus,with the inner shaft distally extending the filter body length;

FIG. 18 is a fragmentary, longitudinal, cross-sectional view of thethrombectomy device of FIG. 17, after the thrombectomy device has beenpartially retracted within a capture tube distal region;

FIG. 19 is a fragmentary, longitudinal, cross-sectional view of thethrombectomy device and capture tube of FIG. 18, after the thrombectomydevice and captured thrombus has been fully retracted within the capturetube;

FIG. 20A is a fragmentary, perspective view of an everting filter devicehaving a bellowed filter body, shown in the compact configuration;

FIG. 20B is a fragmentary, perspective view of the everting filter ofFIG. 20A, shown in the extended, elongate configuration; and

FIGS. 21A-21F are fragmentary, longitudinal cross-sectional views ofproximal portions of some embodiments of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following detailed description should be read with reference to thedrawings, in which like elements in different drawings are numberedidentically. The drawings, which are not necessarily to scale, depictselected embodiments and are not intended to limit the scope of theinvention. Several forms of invention have been shown and described, andother forms will now be apparent to those skilled in art. It will beunderstood that embodiments shown in drawings and described above aremerely for illustrative purposes, and are not intended to limit scope ofthe invention as defined in the claims which follow.

FIG. 1 illustrates the distal portion of an everting filter 50. Evertingfilter 50 may be viewed as having a distal portion 52 and anintermediate portion 54. Distal portion 52 may be further divided into adistal portion distal region 56 and a distal portion proximal region 58.The device can extend proximally to a proximal portion 59.

Everting filter 50 includes a flexible, mesh, filter body 70. Filterbody 70 may be formed of a plurality of wires or strands which can beused to form the mesh filter body through a variety of methods, forexample, braiding, knitting, weaving, helically winding, andcounterwinding. The mesh can be fused at some or all of the fiber orstrand intersection points. The mesh can also be electrospun, and formedof sheet or film having holes formed by laser drilling, punching,dissolving components selectively, and the like. The strands can beformed of material such as wire, which can be metallic wire or polymericwire. The wire may be substantially circular in cross section or mayhave any number of square, rectangular or irregular cross sectionalprofiles.

The mesh is preferably self-expanding. The self-expanding mesh can beformed totally or in part from self-expanding Nitinol, Elgiloy,titanium, or stainless steel wires and the like, and combinationsthereof. The self-expanding mesh can also be formed of engineeringpolymers, for example, liquid crystal polymer, PEEK, polyimide,polyester, and the like. A preferred mesh is formed of Nitinol wires,which can be heat set to the desired expanded shape. The mesh canpreferably be heat set to a desired bias shape using methods such asthose disclosed in WO 96/01591, herein incorporated by reference.Another mesh is highly elastic, and preformed by mechanical overstressto the desired expanded shape. The mesh is preferably made radiopaque bymeans of plating, core wires, tracer wires, or fillers that have goodX-ray absorption characteristics compared to the human body The mesh maybe either partly or totally radiopaque.

Filter body 70 may be seen to have a plurality of pores or openings 74between the filter body strands or wires. The pores have an average poresize over the filter body, where the individual pore sizes may varydepending upon the location over the filter body. Filter body 70 alsohas a proximal opening 77 formed in filter body proximal region 58 usingtechniques such as those disclosed in U.S. Pat. No. 6,325,815 (Kusleikaet al.), which is herein incorporated by reference. Filter body 70 mayalso be considered to have an interior within the filter body and anexterior defined outside of the filter body. Filter body 70 furtherincludes an interior surface 72 and an exterior surface 68. Filter body70 may be seen to extend from a first end region 62 to a second endregion 60. Filter body 70 includes an intermediate region 61 disposedbetween first end region 62 and second end region 60. Filter bodyproximal opening 77 may be seen to have a proximal opening mouth region75 forming the circumference of the opening.

An elongate shaft 80 may be seen to extend distally from proximal region59 and further distally within filter body 70. Unless otherwise noted,shafts in the present invention may be considered to be elongate membersgenerally, being tethers, solid shafts, and tubes in variousembodiments. Shaft 80 is a solid shaft in one embodiment, and can haveat least one lumen therethrough, forming a tube, in other embodiments.

Shafts can be metallic, and formed of Nitinol, stainless steel, Elgiloyor other springy materials, mono-filament or multi-filament, forexample, stranded or cable. The shafts can be tapered or have a uniformdiameter over their length. Shafts can have a circular, flat, or othercross-sectional shape. The shafts can be single member or multi-member,for example, parallel independent structures. Shafts can be coiled andpolymer coated as well as tubular and having a slippery coating.

Some shafts are entirely polymeric, for example, formed of engineeringpolymer, PEEK, polyimide, polyester, PTFE, and the like. Polymericshafts can be reinforced with metals or stiff polymers in the form ofbraids, coils, sheets, ribbons, and the like. Shafts can be partly orentirely constructed of ceramics.

Filter body 70 can be slidably coupled to shaft 80, for example, by aproximal band, ring, bushing or collar 66, typically formed of metal andpreferably radiopaque. In some embodiments, the slidably mounted bandsor rings have a lubricious interior, and can be formed in part ortotally from PTFE. Filter body second end region 60 can be axially,fixedly attached to shaft 80 with a distal band, ring, or collar 64.Filter body 70 has an everted shape. The everting aspect of filter body70 may be considered to divide the filter body exterior surface into anon-everted region 76, proceeding to a distal-most region 78, proceedingfurther over the surface to an everted surface region 82. The evertedshape of filter 70 defines an everted cavity or concave region 83bounded by filter body everted surface region or cavity side walls 82and the filter body distal-most extent. It may be seen from inspectionof FIG. 1 that axially translating proximal ring 66 relative to distalring 64 while holding the filter body diameter consistent may change thedegree of eversion of filter body 70. The filter material occupyingdistal-most region 78 may therefore change with the degree of eversionof filter 70, with different locations of filter body 70 beingdistal-most varying as a function of the degree of eversion. The lengthof a distal cavity 83 will increase with increasing eversion.

The everting nature of the filter bodies may be further understood withreference to a common article of clothing, a sock. A sock may beremoved, allowed to hang toe downward, a hand inserted within theinterior, the distal toe region pinched with fingers from within, andthe pinched region pulled upward, forming an everted toe region which ispulled inside out to form an exterior distal cavity or dimple near theclosed end of the sock. The open end of the sock has a proximal openingbounded by a proximal mouth region. The degree of eversion of the sockmay be increased by moving the pinched region upward or the open enddownward, increasing the amount of material within the distal exteriorcavity. The term filter sock may be used interchangeably with filterbody in describing and claiming the present invention.

FIG. 2A illustrates everting filter body 70 from the side in a firstconfiguration. Filter body 70 has a diameter indicated by D1 and alength L1. Filter body non-everted exterior surface 76, distal-mostexterior surface region 78, and everted surface region 82 is aspreviously discussed with respect to FIG. 1. The relative locations offilter body first end region 62 and second end region 60 may be noted.

FIG. 2B further illustrates filter body 70 in a more elongatedconfiguration relative to that of FIG. 2A. Filter body 70 has a diameteras indicated at D2 and a length as indicated at L2. It may be seen frominspection of FIG. 2B that diameter D2 is smaller than that of FIG. 2Aand length L2 is greater than that of FIG. 2A. The configuration of FIG.2B illustrates the elongatable nature of the filter body, which can beused to decrease the profile. The decreased profile configuration can beused to dispose the radially reduced filter body within filter deliverydevices and tubes. The radially reduced aspect may also be used toinsinuate the filter into small diameter body vessels, for example,distal blood vessels.

FIG. 2C further illustrates filter body 70 in yet another configuration.In FIG. 2C, filter body 70 has a diameter D3 greater than that of FIG.2A, and a length L3, less than that of FIG. 2A. The configuration offilter body 70 in FIG. 2C illustrates one configuration which may beused to expand the diameter of the filter to occupy a body conduit orvessel when the filter body is to be expanded against the vessel wallsto substantially preclude fluid flow from bypassing the filter. Theaxial translation of proximal ring 66 relative to distal ring 64 may beseen to have varied both the length and diameter of the vessel in FIGS.2A-2C. It may be seen from inspection of FIG. 2A that distallytranslating proximal ring 66 relative to distal ring 64 can alsoincrease the degree of eversion of filter body 70, rather thanincreasing the diameter. This aspect of the invention will be discussedfurther.

Referring again to FIG. 1, one method forming the everted filter shapemay be further discussed. Everting the filter can include everting thedistal region of the filter body material to form the everted distalcavity bounded by the filter body exterior surface, as previouslydiscussed. The filter body exterior surface may then be disposed aroundthe exterior surface of the shaft distal end. The filter materialexterior surface can then be operably coupled or mated to the shaftdistal end exterior surface. The coupling of the filter exterior surfaceto the shaft may be accomplished by any method suitable for the filterbody material. Various materials may be suitable for fixing usingwelding, braising, soldering, solvent welding, adhesives, and crimping.The filter body may also be fixed to the shaft using a band, forexample, distal band 64 previously discussed. In a preferred embodiment,distal band 64 and the second end region of the filter body are fixedwith respect to translation and rotation relative to shaft 80. In oneembodiment, distal band 64 is fixed only with respect to translation,being allowed to rotate about shaft 80. This can be accomplished, forexample, by enlarging the extreme distal end of shaft 80 to be largerthan the inside diameter of distal ring 64. This method of everting thefilter body may be seen from inspecting FIG. 1.

Proximal ring 66 may be used in various ways to slidably couple bodyfirst end region 62 to shaft 80. In one embodiment, proximal ring 66 isused to gather together and bind the extreme proximal end of acylindrical tube of filter material, where the filter material can befixed or adhered to the ring interior, and even folded back distallyover the ring exterior and secured to the ring exterior using adhesionor further crimping. In some embodiments, the filter material itselfslides axially over the shaft, being gathered and held in place by theproximal ring.

Filter body 70, along with first end region 62, second end region 82,distal cavity 83, distal-most region 78, non-everted region 76, andproximal opening 77 is used to refer to parts of the everting filtersgenerally. The same reference numbers are used to refer to theselocations for different filters, even though the filters are notidentical and the same reference numerals may reference slightlydifferent physical elements of different filters. It should also beunderstood that distal-most region 78 is used to refer to a regionhaving an area and a length, rather than a point of tangency. Thedistal-most region may often refer to an annular shape having across-sectional area at least about half the cross sectional area of thefilter at its widest part.

Referring again to FIGS. 2A-2C, one use of the everted filter to protectbifurcated and trifurcated vessel may be discussed. Filter body 70 hasan elongated shape and small profile in FIG. 2B, which can be used toadvantage to advance the filter to a vessel site through narrowed vesselregions, for example, past a stenosed vessel region. Once in position, awide profile to occupy the entire vessel cross section is desirable, asis a large interior collection volume for the filter. The filter can bemade to assume a wide profile by bringing the filter first and secondend regions together to shorten the filter length and increase thefilter outer diameter. Such a shape may be seen in FIG. 2C.

In one use, filter body 70 can be advanced past a treatment site that islocated immediately proximal of a bifurcation or trifurcation. Thefilter can be expanded to the bifurcation and then expanded to bothdeploy the filter material across all the branch vessels and to increasethe collection volume of the filter, as in FIG. 2C.

Filter body 70 in FIG. 2C also illustrates another advantage of thepresent invention. A large profile filter body 70 can be used to anchorthe filter against the interior vessel walls to stabilize the positionof the filter. A guide wire can be passed through a lumen in shaft 80,and may continue distally past distal cavity 83. Proximal of filter body70, other devices such as angioplasty devices, guide catheters, andatherectomy devices may be removed over the guide wire and replaced withother devices also passed over the guide wire. This use of the guidewire can act to dislodge the guide wire, which may have takensignificant time and effort to position correctly. The movement of theguide wire can also dislodge previous filter devices passing over theguide wire. The anchoring of filter body 70 against the vessel wallsallows a guide wire to pass through a lumen in the filter device, withthe filter body being able to remain in place and resist movement causedby the guide wire. Another way to accommodate wire motion is for thewire motion to cause more or less filter eversion. The length ofnon-everted region 76 may vary in response to wire motion, but theproximal portion of non-everted region 76 will contact the vessel wallat an unmoving position.

FIG. 3A illustrates an alternate embodiment in the present invention forforming an everting filter 90, with the distal region only being shown.In the embodiment of FIG. 3A, the filter everting is accomplished bybiasing the filter body 70 to assume an everted shape whenunconstrained. The bias to assume the everted shape may be provided byheat setting the material to assume the everted shape whenunconstrained. In one example, Nitinol wire braid can be heat set toassume the shape shown in FIG. 3A when not constrained by a surroundingdelivery tube, and to assume the shape shown in FIG. 3B when constrainedby extreme proximal tension put on filter body 70 from the proximal end.Everting filter 90 may be seen to share some aspects of the inventionpreviously discussed. Filter body 70 may be seen to have interiorsurface 72 and exterior surface 68. Filter body 70 may be seen to extendfrom noninverted region 76, to a distal-most region 78, and further toeverted region 82. Everted region 82 defines an everted cavity orconcave region 83 within, bounded by distal-most region or extent 78. InFIG. 3A, shaft 80 may be seen to have a distal end region 81 having ashaft exterior surface 85 thereabout. Filter body 70 may be seen to haveinterior surface 72 which is mated about shaft distal end 81, toexterior surface 85. The filter body interior surface can thus face theshaft exterior surface directly. In the example illustrated, distal ring64 is disposed about filter body 70 and shaft distal end region 81. Aproximal-most extent of everted cavity 83 is indicated in FIG. 3A at 92.

FIG. 3B illustrates everting filter 90 of FIG. 3A, in a reduced profileconfiguration. Filter body 70 has been proximally retracted from distalring 64. The configuration of FIG. 3B may be understood to be aconstrained configuration, maintained only by proximally drawing filterbody 70 and preventing filter body 70 from freely assuming theunconstrained configuration illustrated in FIG. 3A. The location 92,previously the proximal-most extent of the everted cavity of FIG. 3A maybe noted in FIG. 3B. Everting filter 90, having the alternate evertingdistal region, has one advantage which may be apparent from inspectionof FIG. 3B. In particular, everting filter 90 can have a very lowprofile or distal outer diameter when in the configuration of FIG. 3B.It is not necessary for filter body 70 to extend distally from withindistal ring 64, everting, then extending proximally back over shaft 80.The embodiment of FIG. 3B can be useful where an extremely low profiledistal region is required, for example, for traversing narrow and/ortortuous distal vessel regions.

FIG. 3C illustrates another embodiment of the invention in evertingfilter 94. Filter 94 includes referenced features previously discussed.Everting filter 94 includes a more conical shape than that of theembodiments previously discussed. Everting filter 94 also illustratesthe mode of attachment of filter body to shaft in one preferredembodiment. Filter body 70 includes interior surface 72 and exteriorsurface 68, previously discussed. Exterior surface 72 may be seen facingand mated to shaft exterior surface 85, using methods previouslydiscussed. Distal ring 64 is further disposed about both filter body 70and shaft and distal region 81. The filter body surface non-evertedregion 76, distal-most region 78, and everted region 82 may be seen.Everted cavity 83 may also be seen, being very small in FIG. 3C. FIG. 3Cillustrates a constrained configuration of everted filter 94, whichwould more fully evert, increasing the volume of everted cavity 83 andlength of everted region 82, should filter 70 be allowed to distallytravel to an unconstrained configuration.

FIG. 3D illustrates the distal region of another everting filter 96.Filter 96 includes referenced features previously discussed. Evertedcavity 83 may be seen formed by everted region 82 and distal-most region78. The shape of everted cavity 83 may be seen to be widely separated,formed by a funnel shape to the everted surface walls, where the funnelshape diverges outwardly over the length of the cavity. In particular,the minimum inside diameter of everted cavity 83 is indicated at D5.This minimum inside diameter D5 may be seen to be approximately equal tothat of D4, the outside diameter of shaft 80. In the embodimentillustrated, the everted cavity minimum inside diameter is not less thanthat of the shaft outside diameter, and in some embodiments, can be muchgreater than the shaft outside diameter.

FIG. 3E illustrates yet another embodiment of the invention in evertedfilter 98. Filter 98 has a much less separated everted cavity 83 thanthat of FIG. 3D. In particular, while the walls of the everted cavitymay be seen to diverge over the cavity length in FIG. 3D, the embodimentof FIG. 3E shows the walls distally converging, then diverging. Theeverted cavity minimum inside diameter is indicated at D7. D7 may beseen to be significantly less than outer diameter D4 of shaft 80.

FIG. 3F illustrates still another embodiment of the invention in evertedfilter 99. Everted filter 99 includes referenced details previouslydiscussed with respect to other embodiments. Everted filter 99 alsoincludes a distal tip 97, terminating in an atraumatic and preferablyradiopaque safety tip 95. Distal tip 97 may be useful for insinuatingthe everting filter into narrow and/or tortuous vessel regions. Inparticular, distal tip 97 may be used to at least partially aligneverting filter 99 with the desired orientation indicated by the atleast partially insinuated distal tip 97.

Tips can be metallic, and formed of Nitinol, stainless steel, Elgiloy orother springy materials, mono-filament or multi-filament, for example,stranded or cable. The tips can be tapered or have a uniform diameterover their length. Tips can have a circular, flat, or othercross-sectional shape. The tips can be single member or multi-member,for example, parallel independent structures. Tips can be coiled andpolymer coated as well as tubular and having a slippery coating.

Some tips are entirely polymeric, for example, formed of engineeringpolymer, PEEK, polyimide, polyester, PTFE, and the like. Polymeric tipscan be reinforced with metals or stiff polymers in the form of braids,coils, sheets, ribbons, and the like. Tips can be partly or entirelyconstructed of ceramics. The tips are preferably made radiopaque bymeans of the metal chosen or by means of radiopaque additions such asfillers added to polymer based tips.

FIG. 4A illustrates an everting filter device 100, including a filterbody 70, previously discussed. Everting filter device 100 includes afirst or proximal shaft 102 fixedly attached to filter body 70 withproximal ring 110. In the embodiment illustrated, a portion of filterbody 70 is secured to proximal ring 110. In one example, a portion offilter body 70 may be pulled through a channel in proximal ring 110 andsecured within. In another example, a portion of filter body 70 may besecured to the outside of proximal ring 110. In yet another example, aportion of filter body 70 may be disposed within ring 110, between thering inside wall and the inserted proximal shaft distal end 106.

Filter body 70 may be seen to have a proximal mouth region 114 definingproximal opening 112 therein. In some embodiments, proximal mouth region114 may be formed of the knitted proximal extent of filter body 70. FIG.4A illustrates how a tubular filter body may be used to form the presentinvention, by utilizing the existing proximal filter body opening of thefilter body as the everting filter proximal opening. This may becontrasted with using the existing filter body proximal opening tosecure the filter first end region about the proximal shaft, thereaftercreating the proximal opening by extremely enlarging at least one of themesh pores. Filter body 70 first end region 62 may thus be secured usinga small portion of pre-existing proximal mouth region 114.

In a preferred embodiment, the proximal opening is made by constrainingthe ends of a braided tube with bands, then forcing a pointed mandrelthrough the wall of the braid near the proximal band, and heat settingthe braid to this configuration. The mandrel can have a tapered endwhich forces a pore opening wider as the mandrel is inserted further.The mandrel can also be worked within the selected pore to increase thesize. Some methods of forming a proximal opening are described in U.S.Pat. No. 6,325,815, and in U.S. Published Patent Application No.2002/0004667, both herein incorporated by reference.

A second or distal shaft 104 may also be seen, having a distal endregion 108 secured to filter body second end region 60 using distal ring64. The relative locations of proximal ring 110 and distal ring 64 toeach other can change the size of everted cavity 83 and the length oramount of everted filter material 82. Either shaft 102 or 104 may besolid shafts or have lumens therethrough, depending upon the embodiment.In some embodiments, both proximal shaft 102 and distal shaft 104 may beslidably disposed within a tube or otherwise mounted in a side-by-sideslidable relationship to each other. The use of the terms proximal anddistal to refer to shafts 102 and 104 respectively are used forexplanation, and refer to the configuration resulting in the evertedfilter, as shown in FIG. 4A. It should be understood that, in theexample of FIG. 4A, distal shaft 104 could be retracted proximally ofproximal shaft 102.

FIG. 4B illustrates an everting filter device 120, including many of thereferenced elements of FIG. 4A, which may be understood with referenceto the discussion of FIG. 4A. Everting filter 120 includes proximalshaft 102 and distal shaft 104 as previously discussed. Everting filterdevice 120 can further include a ring or collar 122 which, in variousembodiments, can be fixedly attached to either of proximal shaft 102 ordistal shaft 104, but not both. The shaft which is not fixedly attachedto collar 122 is preferably slidably received within collar 122. Collar122 thus allows one shaft to be maintained in at least a partially,controlled and parallel configuration relative to the other shaft. Oneshaft may be held stationary while the other shaft is slidablytranslated through collar 122. In FIG. 4B, proximal shaft 102 isillustrated as fixed to collar 122 while distal shaft 104 is illustratedas being slidably received within collar 122.

FIG. 4C illustrates an everting filter device 124 including filter body70 secured to distal shaft 104 at distal region 108 with distal ring 64.Everted distal cavity 83 may be seen, as previously discussed. Filterbody 70 includes proximal mouth region 114 and proximal opening 112. Ineverting filter device 124, distal shaft 104 is disposed within a lumen128 within proximal shaft 102. Proximal shaft 102 may be seen toterminate distally at a proximal ring 126. Proximal ring 126 may be seento secure filter body 70 to proximal shaft 102. In filter device 124,the degree of eversion of filter body 70 may be controlled by slidablytranslating distal shaft 104 within proximal shaft 102.

In some embodiments, as will be further discussed, proximal mouth region114 can be reinforced with a proximal loop. The proximal loop can bethreaded through at least one portion of filter body 70. In someembodiments, filter body 70 may not be sufficiently strong or biased toexpand radially and may rely at least in part on the self-expandingnature of the proximal loop. Some suitable proximal loop designs aredescribed in European Patent Document No. EP 1181900, hereinincorporated by reference.

FIG. 5A illustrates an everting filter device 130, similar in somerespects to everting filter device 120 of FIG. 4B. Device 130 includesproximal shaft 102, distal shaft 104, collar 122, and filter body 70,all as previously discussed. Everting filter device 130 differs fromdevice 120 of FIG. 4B in the curved shape of the distal portion ofdistal shaft 104. Distal shaft 104 includes an intermediate region 131disposed proximal of collar 122. Intermediate region 131 may be seen tobe parallel with proximal shaft 102 and, in this region, directly inline with the proximal portion of distal shaft 104. Distal shaft 104 maybe seen to include a first region continuing distally past collar 122,indicated at 132. This region may be seen to extend distally from distalshaft region 131. Continuing further distally, a transverse section 132continues transversely away from the longitudinal axis of proximal shaft102, extending more toward the center of filter body 70 interior.Continuing distally from transverse region 134, a distally extendingregion 136 may be seen, which extends substantially parallel to proximalshaft 102 and distal shaft intermediate region 131.

It may be seen from inspection of FIG. 5A that curved or transverseregion 134 can act as a limit to the proximal travel of distal shaft104. Transverse region 134 may be seen to extend at a first, proximalelbow or transition region 138, and then extend transversely anddistally toward a second, distal elbow or transition region 140. In someembodiments, transverse region 134 may extend perpendicular to proximalshaft 102 and distal shaft region 131. In the embodiment illustrated,transverse region 134 extends transversely while extending distally. Thetransversely extending or curved distal region shafts of the presentinvention can serve to center the filter bodies.

As distal shaft 104 is withdrawn proximally, elbow 138 will ultimatelybe drawn to contact collar or stop 122. At this point, further proximaltravel of distal shaft 104 will be prevented or at least hindered,depending on the embodiment. In some embodiments, this serves to limitthe proximal travel and limit the degree of eversion of the filter body.In other embodiments, first elbow 138 can serve to provide the treatingphysician with tactile feedback as to the degree of eversion. In someembodiments, transverse region 134 can be retracted through collar 122,after a threshold degree of tensile force is applied to distal shaft104. Transverse regions such as transverse region 134 can thus serve tocontrol the degree of filter eversion and can act to prevent theinadvertent over-eversion, reversing the relative locations of thedistal and proximal regions. In some embodiments, elbows 138 and 140 areheat-set and biased to assume the shape illustrated in FIG. 5A, but aresufficiently malleable to allow transverse region 134 to be fullyretracted through collar 122. This aspect can be useful where a smallprofile is desired for delivery, followed by the expansion to theunconstrained configuration illustrated in FIG. 5A.

FIG. 5B illustrates another everting filter device 140, which is similarin many respects to everting filter device 124 of FIG. 4C. Evertingfilter device 140 shares many of the aspects of device 124 of FIG. 4C,and uses the same reference numerals to describe these aspects. Evertingfilter device 140 includes proximal shaft 102 having a lumen 128therethrough which slidably receives distal shaft 104. Proximal shaft102 extends distally to proximal ring 126 which secures filter body 70to the proximal shaft. Filter device 140 differs from filter device 124in having a curved or transverse region 144 in distal shaft 104. Distalshaft 104 includes a region 141 disposed proximal of proximal ring 126,extending distally to a first region 142 disposed distally of proximalring 126 and in line with distal shaft region 141 and proximal shaft102. Continuing distally, distal shaft 104 includes a transverse region144 which extends distally and transversely away from proximal shaft102. In some embodiments, transverse region 104 extends perpendicularlyand transversely away from proximal shaft 102. In the embodimentillustrated in FIG. 5B, transverse region 144 extends distally whileextending transversely more toward the center of the filter bodyinterior.

Continuing distally, distal shaft 104 has a third region 146 extendingdistally from transverse region 144 and substantially parallel toproximal shaft 102 and distal shaft region 141. Transverse region 144can serve the same purpose as transverse region 138 of device 130 inFIG. 5A. Specifically, transverse region 144 can serve to limit theproximal travel of distal shaft 104, thereby limiting the degree ofeversion of filter body 70. Transverse region 144 can also serve toprovide tactile feedback to the treating physician as to theconfiguration of the everting filter body.

FIG. 5C illustrates yet another embodiment of the invention in evertingfilter device 150. Device 150 is similar in many respects to device 130of FIG. 5A. Device 150 shares many of the same aspects of the inventionas device 130 and utilizes identical reference numbers in referencingthese aspects. Everting filter device 150 includes distal shaft 104having region 132 as discussed with respect to device 130. Continuingdistally, distal shaft 104 passes through an elbow 156 then to a firsttransverse region 152, which extends transversely away from proximalshaft 102 while extends distally away from shaft 102. Distal shaft 104then passes through a second elbow 158, then extends distally away fromproximal shaft 102 while extending transversely back toward proximalshaft 102.

Distal shaft 104 then continues along a straight region 162, thenjoining distal ring 64. Distal shaft 104 may be seen to have a firsttransverse region 152 which extends transversally past a center line offilter body 70 and transversally past a center line drawn through distalring 64. Distal shaft 104 then doubles back and extends back toward thedirection from which it came. The u-shape to the distal shaft regionwithin filter body 70 can serve to provide tactile feedback and as alimit or restraint on proximal travel of distal shaft 104 as previouslydiscussed. The extreme degree of transverse travel of transverse region152 can also serve to provide some structural support for filter body 70in the open position, and can act to open filter body 70 where thefilter body itself may benefit from assistance in maintaining orre-attaining the open shape, for example, after being constrained withina delivery catheter or device.

FIG. 6 illustrates in more detail one embodiment of a frictional lockwhich can be used with the present invention. A frictional lock 170 isprovided, and can be used in place of collar 122, depicted in FIG. 5A.Distal shaft 104 and proximal shaft 102 are illustrated as before. Aproximal ring 172 and a distal ring 174 are illustrated disposed ofeither side of frictional lock 170. The relative sizes of the proximaland distal rings are not necessarily to scale. The relative locations ofproximal and distal rings 172 and 174 relative to frictional lock 170are also not necessarily to scale.

In some embodiments, the rings 172 and 174 are disposed significantlyfurther apart than illustrated in FIG. 6, and can serve as the distaland proximal limits to travel of distal shaft 104, and therefore thelimits to the degree of eversion of filter 70. In other embodiments,rings 172 and 174 may be closer together. FIG. 6A illustrates frictionallock 170, having distal shaft 104 inserted through a top lumen 176 andfilter body shaft 102 inserted through a bottom lumen 178. In oneembodiment, proximal shaft 102 is fixedly secured within bottom lumen178, and is not free to slide. Distal shaft 104 is disposed of top lumen176, being free to slide actually through the lumen. Distal ring 174 maybe seen as exceeding the diameter of lumen 176 and preventing orinhibiting travel therethrough. FIG. 6B further illustrates lock 170 ina prospective view.

In some embodiments, rings 172 and 174 do not serve to limit the travelthe distal shaft 104, but instead provide resistance to travel whenexceeding either ring travel limit. In particular, the rings may serveto provide a perceptible bump, giving tactile feedback to the treatingphysician that a limit has been exceeded. In these embodiments, thelimit of travel of the rings may be exceeded prior to deployment of thefilter, for example, while the filter is constrained within the deliverydevice or sheath. A frictional lock such as lock 170 may be used oneither the distal or proximal shaft and may also be disposed at theproximal end of the device in some embodiments. The rings may bereplaced in some embodiments with more gradual bulges or raised regions.

A lock is formed by the bent wire regions 138/140, and 156/158 in FIGS.5A and 5C respectively. When the bent wire is pulled into the collar thewire will resist straightening, and a frictional force of the wireagainst the collar will effectively lock the wire/mesh relative to thecollar/other wire.

FIG. 7 illustrates yet another everting filter device 180 includingfilter body 70 as previously discussed. Everting filter device 180includes both a first proximal opening or port 186 and a second proximalopening or port 188. The present invention may include several proximalopenings for allowing fluid flow into the filter body. In one example,the filter body is formed by gathering together and securing thepreexisting proximal mouth region of a tubular cylinder. Existing poresthrough the filter body wall may then be significantly enlarged byinserting ever larger members through the mesh. The enlarged pores aredesirably heat set to maintain their enlarged shape. In these and otherembodiments, it may be advantageous to form the large cross-sectionalarea openings of the present invention by forming 2, 3 or 4 openings1through the proximal region of a filter body to thereby increase theopening surface area and distribute the openings more symmetricallyabout the shaft.

FIG. 7 also illustrates a proximal ring 199 useful with the presentinvention. Ring 199 includes an inner ring 190 which is slidablydisposed over shaft 182 with a lumen 198. Filter body or mesh materialmay be seen gathered over inner ring 190 at 192. A second or outer ring194 may then be disposed over gathered material 192 and inner ring 190.Outer ring 194 may then be secured to filter body material 192 and innerring 190 through any suitable method, including crimping, as illustratedin FIG. 7.

Everting filter device 180 also illustrates shaft 182 having a distalregion 184 which is biased to gradually slope away from the portion ofshaft disposed proximally of ring 199. Shaft distal region 184 may bedescribed as forming a gradual curved transition from the proximal ringto the distal ring where the distal ring is made to be transversallyoffset from a line drawn through the shaft proximal of the proximalring. As may be seen from inspection of FIG. 7, the biased, distaltransition region 184 can act to at least partially open filter body 70.In some embodiments, biased transition region 184 can also act to centerfilter body 70 within a vessel. Transition region 184 can be biased byheat setting the shaft material. In one example, shaft 182 andtransition region 184 are formed of Nitinol, and are heat set to assumea gradual transversally sloping shape when unconstrained.

FIG. 8A illustrates an everting filter device 200, similar in somerespects, to that described with respect to FIG. 4C. Everting filterdevice 200 is disposed within a delivery tube or catheter 202 which isin turn disposed within a lumen 221 of a body vessel or conduit 222.Delivery tube or catheter 202 can have a distal region 206 and a lumen204 therethrough. Everting filter device has a filter body 70 includinga non-inverting exterior surface region 76, a distal-most region 78, andan everted exterior surface region 82 defining an everted cavity 83therein. Filter body 70 may also be seen to have a first proximalopening 216. Everting filter device 200 includes a distal shaft 208slidably disposed through a proximal shaft 210 which includes a lumentherethrough. Proximal shaft 210 terminates distally at about proximalring 212, which also serves to secure filter body 70 to proximal shaft210. Distal shaft 208 is secured to filter body 70 at distal ring 214.In a preferred embodiment, distal ring 214 is fixedly secured to distalshaft 208 and proximal ring 212 is fixedly secured to proximal shaft210, but allows distal shaft 208 to axially slide through proximal ring212. The degree of eversion of filter body 70 must thus be controlled bythe relative distances between proximal ring 212 and distal ring 214, bythe translating movement of shaft 208.

FIG. 8B illustrates everting filter device 200 after the device has beendistally advanced from delivery catheter 202 and radially expanded anddeployed within vessel 222. Vessel 222 can be any of the coronary,carotid, renal, peripheral, cerebral, neurological, and other bloodvessels. Everting filter device 200 can find one exemplary andadvantageous use in the narrow and tortuous neurological blood vessels.Delivery catheter 202 may, in some uses, be proximally retractedentirely from the body. Body fluid flow, for example, blood flow, mayextend through filter body 70, entering through proximal openings 216,continuing through the filter, and exiting through distal-most region78. After a period of time, filtrate material 220 may collect in thedistal-most region of the filter. After sufficient time, the pressuredrop across the device 200 may become too great, even totally occludingflow through the filter. In prior art devices, at this point in time,the filter would typically be proximally retracted into a capture deviceand removed from the body. The present invention allows changing theeversion of the filter to provide fresh, unoccluded surface area to bepresented to the body fluid flow, thereby postponing the need to removethe filter device from the body, and extending the filter capacity ofthe device. The length of everted exterior surface material 82 may benoted in FIG. 8B.

FIG. 8C illustrates everting filter device 200 after the filter has beenfurther everted. Distal shaft 208 has been proximally retracted, therebydecreasing the distance between proximal ring 212 and distal ring 214.This also decreases the distance between the first and second ends offilter body 70. The volume of the everted cavity 83 may be seen toincrease from FIG. 8B to FIG. 8C. Filtrate 220 may be adhered to theside walls of everted cavity 83. This is common in filtrate materialswhich tend to stick together, for example, thrombus or grumous. Thelength of everted filter material 82 may be seen increased from FIG. 8Bto 8C as well. Distal-most region 78 of everting filter device 200 isnow once again a porous region, permitting fluid flow therethrough. Thepresent invention thus allows fresh filter media to be presented to aperfusing bloodstream without requiring the removal of the filter fromthe patient's body.

After a period of time, the distal-most region such as region 78 of FIG.8C may also become occluded, and distal ring 214 proximally retractedagain, further providing additional unoccluded filter material to thebody fluid being filtered. This process may be continued as long asdesired, or until the filtrate capacity of everting filter device 200has been reached. The degree of eversion of filter body 70 may be eitherincreased or decreased to present unoccluded filter material to theblood flow, depending on the device and the initial degree of eversion.At this time, everting filter device 200 can be proximally retractedinto capture device, for example, into the lumen of the delivery device,such as delivery tube 202, previously discussed. Alternatively, aseparate recovery catheter (not shown) can be used. In an alternateembodiment, recovery of filter device 200 is effected by extendingdistal shaft 208 relative to proximal shaft 210 so as to extend thefilter and reduce its diameter. In this configuration, filter device 200can be withdrawn from the body without use of a capture device.

FIG. 9 illustrates another everting filter device 240, similar in somerespects to everting filter device 100 of FIG. 4A. Everting filterdevice 240 includes the proximal shaft 102 and proximal ring 110previously discussed, as well as distal shaft 104 and distal ring 64.Filter body 70 includes distal everted cavity 83. Device 240 furtherincludes a proximal opening 246 defined within a proximal mouth region242. Proximal mouth region 242 may be seen to include a proximal loop244 within. Proximal loop 242 may be seen to extend around thecircumference of proximal mouth region 242 and be secured to proximalring 110. In embodiments where the proximal mouth region has been formedby piercing the filter sidewall as previously discussed, the loop canremain secured in the filter body by simply intertwining the loop in thefilter. In devices where the proximal mouth region has been produced bycutting the filter such that loose ends of filter strands are present,it will be desirable to weld, bond, or otherwise join at least some ofthe filter body strands so as to prevent filter unraveling or separationwith subsequent disconnection of the loop from the proximal mouthregion.

In some embodiments, filter body 70 is of sufficient strength and issufficiently biased outward so as to not require any support fromproximal loop 244. In this embodiment, loop 244 may be a string, servingas a drawstring though proximal mouth region 242. In other embodiments,filter body 70 may require, or benefit from, an outward radial forceapplied to proximal mouth region 242. In this embodiment, loop 244 maybe formed of a stronger, wire material. In one example, loop 244 isformed of Nitinol or another wire biased to assume a substantiallycircular cross-sectional profile as illustrated in FIG. 9. Loop 244 maybe entirely separate from the filter body 70, being affixed only to theproximal band 110, may be intertwined with the mouth of the filter bodyover much of the proximal mouth region 242, or may be looped through adiscreet region of the filter body, most desirable through the region ofthe filter body diametrically opposed to the proximal band 110. A loopmay be optimally attached to distal band 64 and provide radial expansionto filter body 70. This may be particularly advantageous when filterdevice 240 is used near bifurcations. The loop may be attached to aseparate proximal ring and interwoven through the filter. Loop 244 mayserve as both a proximal mouth region expansion and supporting device,as well as a closure device should everting filter device 240 beproximally retracted within a smaller profile capture device. The loopis preferably partly or entirely radiopaque so as to facilitatevisualization of the proximal mouth region under fluoroscopy. Proximalloops are discussed in detail in European Patent Document No. EP1181900, previously incorporated by reference.

FIG. 10A illustrates another everting filter device 250. Everting filterdevice 250 has only a single shaft 252 terminating in a ring or collar254. Filter body 70 includes end region 62 terminating in a proximalmouth region 256. Filter body second end region 60 may be seen coupleddirectly to collar 254 and shaft 252. Proximal mouth region 256 mayinclude a proximal loop or string within, as previously discussed, inthis figure shown intertwined in the filter body 70 and not attached tocollar 254. Everting filter device 250 further includes fasteningmembers 260 coupling shaft 252 to filter body 70 via collar 254 andproximal mouth region 256. In one embodiment, fastening members 260 arestruts, having significant strength in compression, and are coupled to aproximal loop disposed about mouth region 260. Struts 260 can thus actto maintain filter body 70 in an open position, thereby maintaining thepatency of the proximal opening 258. In some embodiments, struts 260 arebiased to splay outwardly or to assume an arcuate position whenunconstrained. Support members or struts 260 can thus serve to radiallyexpand filter body 70 when deployed from a filter delivery device.

FIG. 10B illustrates everting filter device 250 in a maximally evertedstate, where filter body second end region 60 is proximally retractedand fastening members 260 are proximally extended. FIG. 10C illustrateseverting filter device 250 where shaft 252 has been maximally distallyextended, thereby changing device 250 to the minimally everted state.Support members 260 may be seen as taut and maximally distally deployed.Where fastening members 260 are tethers, device 250 may be deployed inconfigurations intermediate those of 10B and 10C, thereby graduallyincreasing or decreasing the degree of eversion of filter 70. Device 250may find one use where proximal mouth region 250 would expand radiallyoutward beyond the vessel boundaries, thus fixing the location of thefilter within the vessel and providing support for maintaining thefilter position as filtrate is collected within the filter interior. Inparticular, as more filtrate is collected, device 250 may be graduallyswitched from the configuration of FIG. 10C to that of FIG. 10B. Device250 may then be proximally retracted into a capture device, withfastening members 260 assisting in closure of proximal mouth region 256as the filter is retracted and proximal opening 258 is closed. Device250, as shown in FIGS. 10B-10C, further illustrates that filter body 70can maintain a stable position in a vessel despite large motions ofshaft 252.

FIG. 11 illustrates an everting filter device 280 having a shaft 284terminating distally in a distal ring or band 282 which secures thesecond end region of filter body 70 to shaft 284. Filter body 70 has aproximal mouth region 286 having at least one drawstring 288 threadedtherethrough. In the embodiment illustrated, drawstring 288 is threadedthrough proximal mouth region 286. Shaft 284 has a lumen 290therethrough. Shaft 284 further includes a port 292 extending from theshaft exterior to lumen 290. Drawstring 288 extends from proximal mouthregion 286 through port 292 and proximally through lumen 290 of shaft284.

In use, filter body 70 can be constrained and significantly radiallyreduced in profile to fit within a delivery sheath or other deliverydevice. In some methods, drawstrings 288 will be pulled taut andproximal, substantially reducing the profile of proximal mouth region286 as well. In one embodiment, filter body 70 is sufficiently outwardlybiased and firm so as to not require the outward biasing force of a loopwithin proximal mouth region 286. Filter body 70 can be released ordistally ejected from the filter delivery device and allowed to expandradially outward within the body vessel or conduit to be filtered. Inone method, proximal mouth region is dimensioned to have anunconstrained diameter greater than the diameter of the vessel region tobe filtered. Filter body 70 preferably has a nominally cylindrical shapewhere the majority of the cylinder also has a unconstrained diametergreater than the diameter of the vessel region to be filtered. Theunconstrained filter body 70 is thus allowed to expand outwardly againstthe vessel walls, while still exerting some force and thereby at leastpartially anchoring filter to the vessel walls to the outward expansionforce.

In some filter body embodiments, blood flow is partially or totallyresponsible for expanding the filter body against the vessel wall. Asthe distal-most region 78 becomes occluded with filtrate, shaft 284 canbe retracted proximally, thereby bringing previously noneverted exteriorfilter surface 76 away from the vessel wall and taking the place of thedistal-most region 78. In this way, unoccluded filter regions can besupplied without withdrawing the filter device from the patient. Whenthe filter device has reached its capacity or the procedure is complete,drawstrings 288 may be used to at least partially close proximal opening287. The at least partially closed filter device can be withdrawn fromthe patient's body directly or retracted into a capture device or sheathand then removed from the patient's body. Alternatively the filterdevice can be partially retracted into a capture device or sheath andthe combination with partially unsheathed filter withdrawn from thepatients body.

In another embodiment, drawstrings or tethers 288 are secured to filterbody 70 at different locations about the proximal mouth region 286.Drawstrings 288 may be disposed at 180 degree, 120 degree, 90 degree, orother substantially equal distant intervals about proximal mouth region286. An outwardly biased stiffening loop may be disposed about proximalmouth region 286 as well. In some devices, drawstrings 288 are coupledto the proximal mouth region and/or the proximal loop member. In thisembodiment, another method may be practiced. The same method may bepracticed in other embodiments, not requiring the stiffening proximalloop.

In this method, filter body 70 is allowed to expand after beingdelivered to a target vessel region to be filtered. The drawstrings 288disposed about proximal mouth region 286 can serve to tether proximalmouth region 286 to shaft 284. The degree of eversion of filter device270 can thus be controlled by the relative movements of drawstrings 288within lumen 290 and the position of shaft 284. In one example, to morefully evert filter device 70 and increase the volume of everted cavity83, shaft 284 may be proximally retracted while distally advancingdrawstrings 288 through lumen 290. In this way, in some methods, theabsolute position of proximal mouth region 286 within the vessel may bemaintained, while proximally retracting distal ring 282 and therebyincreasing the degree of eversion of filter device 70. When thefiltering process is finished, drawstrings 288 may, in some methods, beused to reduce the proximal profile of proximal opening 287, followed byretracting device 280 from the patient's body. In some methods, thisproximal retraction is carried out by first retracting device 280 withina filter retrieval device or sheath in whole or in part. It may be notedthat in some devices, such as those having the drawstrings spaced aboutthe proximal mouth region and having the proximal mouth region and/orfilter body sufficiently biased to maintain an open shape, it may not benecessary for the filter body to expand against the enclosing vesselwalls to anchor the filter device to allow control of everting.

FIG. 12A illustrates a filtering/occluding device 300. Device 300 issimilar in many respects to device 140 of FIG. 5B and includes many ofthe identically numbered elements previously described. Device 300includes proximal shaft 102 having a distal shaft 104 disposed within,where shaft 104 includes a transverse region 144 which curves distal ofproximal ring 126 and extends transversely away from proximal shaft 102.Transverse region 144 is included in some embodiments of thefiltering/occluding device, but not others. Filter body 70 includes afiltering portion 304 and an occluding portion 302. In some devices,occluding portion 302 includes the same mesh materials as filteringregion 304, and further includes an occluding film disposed over orwithin the filtering mesh material. In some embodiments, a polymericfilm, for example polyurethane, silicone, latex, polyethylene, and thelike is disposed over or within a wire mesh material forming thefiltering portion 304.

In device 300, occluding region 302 is disposed distally of filteringregion 304. Occluding region 302 is thus disposed closer to andapproaches filter body second end region 60, while filtering region 304is disposed closer to and approaches filter body first end region 62.

Filtering/occluding device 300 and most of the other filter bodiespreviously discussed may be considered to have a longitudinal flowchannel through the device. A longitudinal flow channel may be seenentering at proximal opening 112 and continuing through the filter bodyinterior, exiting through the filtering region 304. In configurationswhere the filter body is substantially completely occupying a vesselinterior, flow around the device, between the device and the vesselwalls, may not be possible. In such situations, the only flow throughthe device may be through the interior, with a substantial portion ofthe flow being through a proximal opening, such as proximal opening 112in device 300. In devices some device configurations filtering region302 is presented across substantially the entire vessel inside diameterand across substantially the entire filter device flow channel. It maybe sent that in device 300, by distally extending shaft 104, occludingregion 302 may expand transversely to more fully occlude a vessel device300 is inserted within. Device 300 may thus be considered to operate byextending occluding region 302 across a vessel interior to partially,substantially, or totally occlude the vessel interior.

FIG. 12B illustrates filtering/occluding device 300, shown in afiltering configuration rather than an occluding configuration. Shaft104, including transverse region 144, has been proximally retractedrelative to the position in FIG. 12A. Filter body 70 has been more fullyeverted, bringing filter body material previously disposed along theside to the distal-most portion and to the everted cavity interior. Thevolume of everted cavity 83 may be seen to be greater, and the length ofthe cavity greater, relative to that of FIG. 12A. Occluding region 302may be seen to be now lining the interior of everted cavity 83.Distal-most portion 78 is now occupied by filter material rather thanoccluding material. By comparing FIGS. 12A and 12B, it may be sent thatfiltering/occluding device 300 may be switched between a filtering andoccluding mode by the advancement and retraction of shaft 104.

FIG. 13A illustrates another filtering/occluding device 326. Device 326is similar in many respects to device 300 of FIGS. 12A and 12B. Indevice 326, the relative positions of the occluding region and filteringregion have been changed relative to those of device 300. In device 320,as illustrated in FIG. 13A, a first filtering region 324 is disposednear filter body second end region 60, with occluding region 326disposed between the first filtering region 324 and filter body firstregion 62. In the embodiment illustrated in FIG. 13A, a second filteringregion 328 is disposed between occluding region 326 and filter bodyfirst end region 62. In the configuration shown in FIG. 13A, fluid flowis possible through proximal opening 112 and continuing throughdistal-most region 78, occupied by filtering material in filteringregion 324.

In FIG. 13B shaft 104 and transverse region 144 have been proximallyretracted, thereby more fully everting filter body 70, and increasingthe volume and length of everted cavity 83. It may be seen that thelength of everted cavity 83 is greater in FIG. 13B than in FIG. 13A. InFIG. 13B, everted surface region 82 is occupied by filter material infiltering region 324. Distal-most region 78 is now occupied by occludingmaterial in occluding region 326. By proximally retracting shaft 104,the filtering material disposed across the vessel cross section has beenreplaced by the occluding material disposed across the vessel crosssection.

FIG. 14 illustrates a drug delivery device which can be used to deliverdrugs, therapeutic agents, or diagnostic agents into the vessel orpreferentially to the vessel wall. Agents can include restenosisinhibitors, thrombolytic agents, growth factors, biologically activeproteins, and the like. Drug delivery device 340 is similar in manyrespects to the filtering/occluding device 300 of FIG. 12A and includesidentical reference numbers for similarly described elements. In device340, occluding region 302 may be seen to occupy everted surface region82. Filtering region 304 may be seen to occupy the non-everted surfaceregion 76 and distal-most region 78. Filtering region 304 thus facesvessel walls 222. Everted cavity 83 and everted region 82 may be seen tohave been formed, in device 340, using the embodiment discussed withrespect to FIG. 3A. In particular, everted region 82 has been formed ofmaterial heat-set or otherwise biased to form an everted distal tip whenunconstrained. Preferably the everted surface region 82 will be heat setto be nearly as large as the vessel inside diameter so as to minimizethe blood volume between the surface region 82 and the surface region76, thus localizing the delivered drug in the general vicinity of thevessel wall. In other embodiments, drug delivery devices similar todevice 340 can be formed not requiring the bias to form an evertingdistal tip when unconstrained. Specifically, in some drug deliverydevices, the configuration of FIG. 3B may be more illustrative of theunconstrained state of the drug delivery distal tip when unconstrained.

Infusion of agents through device 340 is indicated in FIG. 14 at 342. Insome embodiments, a separate drug infusion tube may be added to infusethe agents. In the embodiment illustrated, an annular infusion lumen isformed between shaft 104 and shaft or tube 102, in the lumen between theinner shaft and the outer tube. Drugs or other agents may thus beinjected at a proximal location in shaft 102, exiting from or nearproximal ring 62, but being substantially blocked by everting region 82and occluding region 344 from being carried downstream. The agents,however, are free to contact vessel walls 222 through non-evertedsurface regions 76 which are occupied by filtering material 304.

In one method, drug delivery device 340 can be advanced to a vessel siteto be treated, using methods previously described. These methods caninclude advancing device 340 over a guide wire and/or within the distalregion of a delivery device or sheath. Device 340 can be deployed, andallowed to expand radially. In some methods, device 340 is maintained ina filtering mode until delivery of the agent is desired. This may beadvantageous in the coronary blood vessels where angina would resultfrom prolonged maintenance in the occluding mode. Device 340 may bemanipulated, for example, by longitudinally moving shaft 104 to changethe device mode to the occluding mode, as illustrated in FIG. 14. Theagent may then be infused, for example, through shaft 102 and allowed tocontact vessel walls 222. Device 340 may then be manipulated to assumethe filtering mode, allowing blood flow, followed by repeated occluding.

The agent delivery step, occluding step, and the filtering or perfusingstep may be repeated as often as necessary. In coronary applications,this may allow a substantial period of drug delivery more directly tothe vessel walls while allowing intermittent periods of perfusing bloodflow. When agent delivery is no longer desired, device 340 may beretracted proximally from the patient's body, for example, by retractingthe device into a recovery catheter or sheath, as previously described.

FIG. 15A illustrates another filtering/occluding device 360. Device 360is similar in some respects to devices 100 and 120 illustrated in FIGS.4A and 4B. Similar elements are referenced with reference numeralspreviously described. Device 360 also shares some functional andstructural aspects with devices 300 and 320 of FIGS. 12A, 12B, 13A, and13B.

Filtering/occluding device 360 includes a proximal shaft 102 coupled tothe filter body first end region 62. Distal shaft 104 is coupled tofilter body second end region at distal band, bushing, or ring 64.Filter body 70 may be seen to have an everted distal cavity 83, adistal-most region 78, and a non-everted surface region 76, aspreviously described. Device 360 also includes proximal opening 112.Device 360 includes an inflatable element, represented by an inflatableballoon 361. Balloon 361 includes a balloon envelope 362 extending to aproximal waist 372 and secured with a securing band or region 365 toshaft 104. Balloon envelope 362 also extends distally to a distal waist370 for securing or bonding to distal ring or band 64. Balloon 361 caninclude an inflation tube 364 extending through the balloon interior 368and having inflation ports 366 therethrough. In some embodiments,inflation tube 364 is a continuation of shaft 104, where shaft 104 hasan inflation lumen therethrough. Balloon envelope 362 can be formed ofballoon envelope material used for inflatable angioplasty balloons, wellknown to those skilled in the art. Typical balloon envelope materialsinclude nylon, polyester, polyethylene, PEBAX, silicone, polyurethane,latex, and the like and may be oriented, preferably biaxially, orunoriented.

In use, device 360 may be advanced to a target site within a vesselthrough a delivery sheath or over a guide wire. Shaft 104, for example,may include a guide wire lumen therethrough. Rapid exchange embodimentshaving a separate guide wire tube and lumen extending over only over adistal region are also within the scope of the invention. When disposedat the target vessel region, balloon 362 can be inflated by providinginflation fluid through shaft 104, through inflation ports 362 and intoballoon interior 368. With balloon 362 inflated, the flow channel orpath through the vessel is completely or substantially blocked. In thismode, particulate flow past balloon 362 is essentially precluded. Theparticulate mater or filtrate may be allowed to gather proximal ofinflated balloon 362 and be aspirated, removing most or all of thematter blocked by inflated balloon 362. When perfusing fluid flow orblood flow is desired, balloon 362 can be deflated and collapsed byremoving the inflation fluid, and in some methods, pulling a vacuum onballoon interior on 368 through shaft 104. With balloon 362 collapsed, aperfusing fluid flow through device 360 is once again established.Particulates or filtrate not removed during an aspiration step may stillbe captured by filter body 70. In this way, some methods may capturemuch of the filtrate using the occluding, inflated balloon followed byaspiration, follow by reliance on the mesh filter material of filterbody 70 to capture material which was not removed during aspirationand/or flows into filter body 70 after the aspiration step. As filtrateis captured near the distal-most region 78, filter body 70 may befurther everted by proximally retracting shaft 104, as previouslydiscussed with respect to other devices. After the filtering step orsteps are complete, device 360 may be removed from the patient's body.In some methods, device 360 is removing by retracting the deviceproximally into a capture sheath or other device. In one method, shaft104 may be proximally retracted during or after the filtering step orsteps. Balloon 362 can be partially or fully inflated to prevent anyloss of filtrate through proximal opening 112 during some or all of theretraction steps.

Filtering/occluding devices for example devices 300, 320, and 360, maybe used in many applications. The filtering/occluding device may beadvanced distally past thrombosed or stenosed regions to be treated. Thedevice may be maintained in the filtering mode during periods in whichonly a small amount of filtrate material is expected to be carrieddownstream to the filtering/occluding device. When heavier material flowis expected, such as during stent expansion or balloon predilatation,the device can be manipulated into the occluding mode, ensuring almosttotal blockage of particulate matter from downstream travel. Thematerial may then be aspirated, and the device manipulated back to thefiltering mode.

In one use, the filtering/occluding or perfusing/occluding device may beused in the filtering or perfusing mode during radiopaque dye injection,and used in an occlusive mode for the remainder of the procedure. Inanother use of such filtering/occluding devices, the devices may be usedprimarily in either the occluding or filtering mode, depending on thejudgment of the treating physician. In such use, a singlefiltering/occluding device may be provided for both primarily filteringor occluding uses, and physicians may choose to utilize the device forprimarily the occluding or filtering modes. A single device may thus becarried which can be put to either filtering or occluding use, notrequiring the stocking of both devices. The choice of a filtering oroccluding device may thus be postponed well past the point of purchaseand even past the point of insertion into the patient. The choicebetween an occluding device or filtering device may thus be made duringtreatment, after the filtering/occluding device has been deployed, forexample, downstream of a vessel blockage to be removed.

FIG. 16 illustrates a thombectomy device 360, similar in many aspects tofilter device 140 illustrated in FIG. 5B. Thombectomy device 360includes shaft 102 coupled to filter body 70 and having distal shaft 104slidably disposed within shaft 102. Thombectomy device 360 may befurther understood by reading the description of device 140, previouslydescribed.

Thombectomy device 360 has a proximal opening 112 and a proximal loop364. Proximal loop 364 is preferably sufficiently rigid and can bebiased to expand radially outward and to maintain a sufficiently rigidshape when encountering a thrombus such as thrombus 362. In someembodiments, proximal loop 364 has a proximally leading edgesufficiently narrow or sharp to cut through or dislodge thrombus 362. Insome embodiments, proximal loop 364 is formed of Nitinol wire biased tofirmly engage vessel wall 222. Proximal loop 364 may be threaded throughfilter body 70 at location 365 indicated near vessel wall 222, oppositeshaft 102. In other embodiments, proximal loop 364 may be threadedthrough the proximal mouth region of filter body 70 in numerouslocations about the mouth region. Thombectomy device 360 may be deployeddownstream of thrombus 362 using methods previously discussed, includingdye catheters, and delivery tubes.

FIG. 17 illustrates thombectomy device 360 after proximal loop 364 hasbeen pulled through thrombus 362. While shaft 102 has been proximallyretracted, distal shaft 104 has been distally advanced relative to theretracting proximal shaft 102. The degree of eversion of filter body 70may be seen to be greater in FIG. 16 than in FIG. 17. Filter body 70 hasbeen elongated, during the capture of thrombus 362.

FIG. 18 illustrates thrombus 362, captured within device 360, withdevice 360 being retracted proximally into a capture device or tube 366having a lumen 368 therethrough. As previously discussed with respect toother embodiments, proximal loop 364 may be at least partially closedprior to or during the proximal retraction step. The proximal mouth canbe substantially closed by retraction into tube 366, and once thisoccurs thrombus 362 will be entirely captive within device 360.

FIG. 19 illustrates thombectomy device 360 after being proximallyretracted within capture device 366. Capture device 366, thombectomydevice 360, and thrombus 362 may be proximally retracted from thepatient.

FIG. 20A illustrates filter body 70 having a bellows shape. While filterbody 380 may be used in conjunction with any of the previously discussedembodiments, one preferred use is in forming the filter body ofthombectomy devices, such as thombectomy device 360. The filter bodyused for thrombectomy devices can be formed of a polymeric film ratherthan a porous mesh in some devices, or by a combination of the mesh witha film. Device 380 may be seen to have a bellows configuration, havingthe filter body length substantially foreshortened during proximalretraction of shaft 104. The excess filter body material which willultimately be used to extend the length of the filter may be bunched orfolded upon itself along regions of preferential folding 382. Regions ofpreferential folding 382 may be formed by wire hoops, heat set regions,and any of a number of shape memory materials commonly known to thoseskilled in the art. Regions of preferential folding may also be formedby ribs set into the filter material. Regions of preferential folding382 may be seen to form a series of valleys 364 separated by peaks 386.FIG. 20B illustrates device 380 in an elongated configuration. Device380 can provide a high ratio between the elongated length and theshortened length. The bellows shape can provide a high ratio betweenfilled length and deployed length.

Thrombectomy device 380 can be deployed through a small catheter distalto a thrombus or other blockage material. The deployed shape ispreferably the shortest shape so as to minimize the length needed fordeployment. The device may be delivered within a catheter in anelongated shape and then deployed out the end of the catheter by pushingon shaft 102 while only slightly retracting the catheter so as to deploythe maximally shortened length immediately distal to the deploymentcatheter. Typically the catheter is then removed. Shaft 102 can be usedto draw filter body 70 through the thrombus, with a proximal loopdislodging the thrombus from the vessel wall, and the thrombus enteringand lengthening the filter body. The thrombus filled filter body can bepartially retracted into a recovery catheter to close the proximal loopand proximal opening. The filter body can be either retracted furtherinto the catheter or the recovery catheter retracted from the patientcoupled to the partially retracted filter body. In one embodiment, thethrombectomy device of FIGS. 20A and 20B has an everted distal region.In another embodiment, the thrombectomy device of FIGS. 20A and 20B doesnot have an everted distal region.

FIG. 21A illustrates a proximal handle portion 400 including an outertube 402 and an inner shaft 408. Proximal handle portion 400 can be usedin embodiments having a shaft extending distally from a tube, such asthe example of FIG. 4C. Outer tube 402 includes a proximal region 404having a proximal port 406 having shaft 408 extending proximally fromthe tube. Shaft 408 is preferably closely fit and slidably disposedwithin tube 402.

FIG. 21B illustrates a proximal handle portion 410 which can be used indevices having tethers or drawstrings, for example the deviceillustrated in FIG. 11. Proximal handle portion 410 includes an outertube 412 having a proximal region 414 and a lumen 413 within. A handle416 can be slidably disposed within tube 412 and have tethers 417attached to the handle. Handle 416 can have a proximal region 418 havingan outer diameter indicated at 411, where the outer diameter can belarger than the inside diameter of the tube, and can be about 0.014 inchor larger in some embodiments. Handle 416 can also have a stepped downdiameter portion 419 adapted to slidable fit within tube 412. Thetethers can be proximally retracted by proximally retracting handle 416.

FIG. 21C illustrates a proximal handle portion 420 which can be used indevices having tethers or drawstrings, for example the deviceillustrated in FIG. 11. Handle portion 420 can have a tube 422 having around portion 424, a more proximal cut-away portion 425, and a proximalend 423. Tethers or drawstrings 436 can be disposed within tube 422 andextend proximally from an opening 434 disposed between an insert 426 andtube round portion 424. The length of opening 434 is indicated at 432,and is preferably long enough to allow the tethers to easily egress thetube. An insert 426 can be disposed within tube 422, and can be withincutaway portion 425. Insert 425 can be formed of an elastomericmaterial, may be formed within and bonded to the tube, and have a slit428 formed into the insert. Slit 428 can be used to lock down thetethers into the slit while allowing the tethers to be pulled free ofthe insert and proximally retracted. The outer diameter of tube 422 isindicated at 430 and can be about 0.014 inch in one embodiment. Thesmall inside diameter and long length, nominally 145 cm, of the tubewill substantially reduce or preclude any blood loss through opening434.

FIG. 21D illustrates a proximal handle portion 440 including a tube 442which can be used in devices having a drug delivery lumen or aninflation lumen disposed within the tube. A tee connector 441 havingsidearms 452, a lumen 454, and Tuohy-Borst fittings 456 and 458 isdisposed about tube 442. Tee connector 441 can include an injection port462 which can be used to inject drugs into the connector and tube. Tube442 can have a proximal port 446 having an inner shaft or elongatemember 448 extending proximally from the tube, with the shaft extendingfurther proximally through proximal fitting or seal 458 through aproximal port 460, terminating in a shaft proximal region 450. Shaft 448can thus slide within tube 442. In some embodiments, port 446 is theproximal port for an annular lumen formed between tube 442 and shaft448.

FIGS. 21E and 21F illustrate a proximal handle portion 480 including anouter tube 482 and an inner shaft 481. Proximal handle portion 480 canbe used in embodiments having an inflatable balloon, such as the exampleof FIGS. 15A and 15B, as well as other examples of the invention. Outertube 482 includes a proximal region 484 having a proximal port 487 withshaft 481 being proximally accessible for manipulation from outside ofthe tube. A handle 485 may be seen to have a large outer diameterportion 486, a stepped down portion 488 slidably disposed within tube482, which is coupled to inner shaft portion 489. Tube 482 can have aport or microhole 485 in communication with tube lumen 483. In theconfiguration of FIG. 21E, microhole 485 is blocked by handle steppeddown portion 488 In the configuration of FIG. 21F, microhole 485 is notblocked by the handle, which has been proximally retracted.

The porous mesh filter bodies of the present invention can be formed ofstrands, ribbons, or wire, where the materials forming the strands,ribbons, or wires can be metallic or polymeric. Non-limiting examples ofsuch materials include Nitinol, stainless steel, Elgiloy, spring steel,beryllium copper, nylon, PEEK, PET, liquid crystals, polyimide, andshape memory alloys and polymers generally. Elastomeric polymers can bealso be used to form the strands and filter bodies. The elastomericpolymers can be formed, shaped, or post processed to achieve the desiredshape. Examples of elastomeric polymers include butyl rubber, naturalrubber, latex, and polyurethanes. The strands or wires can havecircular, square, rectangular, or irregular cross-sectional shapes. Inone filter, the strands or wires have an outer diameter between about0.001 inch and 0.010 inch. The mesh can be any mesh having suitableporosity for the intended use, for example, for allowing perfusing bloodflow while capturing emboli. Examples meshes include braids, knits,interlocking rings or polygons, weaves, helically wound patterns, andnon-woven meshes formed from chopped strand fibers. The filters caninclude radiopaque markers, for example, platinum wires disposed in themesh or radiopaque coatings applied to the strands, or the strands canbe composites of radiopaque and radiolucent materials disposed forexample in a coaxial relationship.

The mesh filter bodies may be made using methods similar to thosedescribed in U.S. Pat. No. 6,325,815 and PCT Publication No. WO96/01951, both herein incorporated by reference. In one method, aone-layer braided Nitinol mesh cylinder is threaded through the lumen ofa forming cylinder, folded over the forming cylinder rounded nose,folded back on the outside of the forming cylinder, and heat set. Thisresults in a pre-stressed braid that can easily recoil in a similarmanner to a spring. A dense braid, having a high number of picks perinch (PPI) is preferred. One filter embodiment has between about 50 and400 PPI.

Some meshes are selected to have an average pore size large enough toallow perfusing blood flow while small enough to capture emboli. Variousmeshes have average pore sizes of at least about 20, 50, and 100microns. The meshes used for the perfusing/occluding embodiments of theinvention may have larger average pore size, in embodiments intended foronly perfusing and occluding rather than filtering and occluding. Someembodiments of the drug infusion device, previously described, caninclude a large pore size region intend to provide structure and allowdrug passage rather than providing significant filtration capturecapacity for emboli.

The curved or transversely extending shaft distal regions found withinsome filter bodies can be formed of Nitinol, heat set to assume a bent,curved, or S-shape when unconstrained. In some methods, the shaft isformed of Nitinol wire, heat set at about 600 degrees C.

The dimensions of the various everted filter devices may vary, dependingon the intended application. The dimension ranges required are wellknown to those skilled in the art. The device dimensions may be dictatedby the expected vessel inner diameters, the distance from the point ofinsertion to the vessel region to be treated, and the dimensions ofother instruments to be used concurrently in the same vessel. In oneexample, filters intended for use in filtering carotid arteries areexpected to be larger than those for coronary artery applications, whichare likely larger than those for use in the cerebral arteries.

Some everted filter devices have elongate member lengths ranging fromabout 50 cm to about 320 cm. In one group of embodiments, the outerdiameter of tethers range from about 0.001 inch to about 0.005 inch, theouter diameter of solid shafts range from about 0.008 inch to about0.035 inch, and the outer diameter of tubes range from about 0.010 inchto about 0.035 inch. In some filter bodies, in the fully elongated statethe length is between about 10 mm and 50 cm, while the outer diameter isbetween about 2 mm and 35 mm. In a fully radially expanded and shortenedstate, some filter bodies can have a length of between about 2 mm and 10mm, while the outer diameter can be between about 3 mm and 38 mm. Theproximal opening size may have an average width of between about 1 mmand 35 mm. In some filters, the average pore size can increase by about5000 percent from the most compressed to the most expanded state. Asused herein, the term “pore size” refers to the diameter of the largestsphere that will fit through the pore. A pore can become elongated asthe mesh is elongated. The elongated pore may have a very large widthand a very small height, therefore having a very small pore size.

What is claimed is:
 1. A device comprising: a shaft having a distal end;and a filter body having an open proximal end and a closed distal end,the filter body being configured to expand from a delivery configurationto a filtering configuration in which the filter body is expanded to avessel engaging diameter, the filter body in the filtering configurationhaving at least first and second filtering positions, the vesselengaging diameter of the filter body being maintained in both the firstand second filtering positions, and a first length of the filter bodyalong the shaft in the first filtering position being less than a secondlength of the filter body along the shaft in the second filteringposition, the closed distal end of the filter body being connected tothe distal end of the shaft, the distal end of the shaft beingpositioned within the filter body such that the closed distal end of thefilter body forms an everted portion.
 2. The device of claim 1, whereinthe filter body is slidably coupled to the shaft.
 3. The device of claim1, wherein a proximal loop is attached to the filter body near the openproximal end, and wherein axial translation of the proximal loop alongthe shaft relative to the distal end of the shaft changes a degree ofeversion of the everted portion.
 4. The device of claim 1, wherein aproximal loop is attached to the filter body near the open proximal end,the proximal loop having a leading edge that is sharpened.
 5. The deviceof claim 1, wherein a first volume of the filter body in the firstfiltering position is less than a second volume of the filter body inthe second filtering position.
 6. The device of claim 1, wherein theproximal end of the filter body is connected to a proximal ring and thedistal end of the filter body is connected to a distal ring, whereintranslating the proximal and distal rings relative to each other whilethe filter body is in the filtering configuration changes a degree ofeversion of the filter body.
 7. The device of claim 1, wherein theeverted portion has a first degree of eversion when the filter body isin the first filtering position and a second degree of eversiondifferent than the first degree when the filter body is in the secondfiltering position.
 8. The device of claim 1, wherein the filter bodycomprises a filter mesh.
 9. The device of claim 8, wherein the filtermesh is self-expanding.
 10. The device of claim 1, wherein the filterbody has a bellows shape comprising regions of preferential folding. 11.The device of claim 10, wherein the regions of preferential folding areformed by wire hoops, heat set regions, shape memory materials, or ribs.12. The device of claim 1, wherein the everted portion defines aneverted cavity, and wherein the shaft is a first shaft, the devicefurther comprising a second shaft attached to the filter body, the firstand second shafts being movable relative to each other to change a sizeof the everted cavity.
 13. The device of claim 12, wherein the firstshaft has a curved region or a transversely extending region thatengages with a collar positioned around the first and second shafts tolimit proximal travel of the first shaft relative to the second shaft.14. The device of claim 12, wherein at least one of the first shaft orthe second shaft defines a proximal ring and a distal ring, the devicefurther comprising a frictional lock configured to engage with theproximal ring and the distal ring to limit a degree of relative movementbetween the first and second shafts.
 15. The device of claim 1, furthercomprising a drawstring connected to the open proximal end of the filterbody, wherein pulling the drawstring towards a proximal end of the shaftat least partially closes the open proximal end of the filter body. 16.The device of claim 1, further comprising a plurality of drawstringsconnected to the open proximal end of the filter body, the shaft and thedrawstrings being movable relative to each other to control a degree ofeversion of the everted portion of the filter body.
 17. A methodcomprising: introducing a device into a vessel of a patient, the devicecomprising: a shaft having a distal end; and a filter body having anopen proximal end and a closed distal end, the filter body beingconfigured to expand from a delivery configuration to a filteringconfiguration in which the filter body is expanded to a vessel engagingdiameter, the filter body in the filtering configuration having at leastfirst and second filtering positions, the vessel engaging diameter ofthe filter body being maintained in both the first and second filteringpositions, and a first length of the filter body along the shaft in thefirst filtering position being less than a second length of the filterbody along the shaft in the second filtering position, the closed distalend of the filter body being connected to the distal end of the shaft,the distal end of the shaft being positioned within the filter body suchthat the closed distal end of the filter body forms an everted portion;and, subsequently, expanding the filter body to the vessel engagingdiameter.
 18. The method of claim 17, further comprising: capturingblockage material within the filter body; and proximally retracting thefilter body.
 19. The method of claim 18, wherein proximally retractingthe filter body includes increasing an axial dimension of the filterbody.
 20. The method of claim 18, wherein proximally retracting thefilter body comprises proximally retracting the filter body to move theblockage material into a capture tube of the device.
 21. The method ofclaim 17, wherein a proximal loop is attached to the filter body nearthe open proximal end, the method further comprising axially translatingthe proximal loop along the shaft relative to the distal end of theshaft to change a degree of eversion of the everted portion.
 22. Themethod of claim 17, wherein the everted portion defines an evertedcavity, and wherein the shaft is a first shaft, the device furthercomprising a second shaft attached to the filter body, the methodfurther comprising moving the first and second shafts relative to eachother to change a size of the everted cavity.
 23. The method of claim17, wherein the device further comprises a plurality of drawstringsconnected to the open proximal end of the filter body, the methodfurther comprising moving the drawstrings relative to each other tochange a degree of eversion of the everted portion of the filter body.